The Metal Storm grenade launching system is a radical step from most conventional firearms. Using the ancient principle of an "Roman candle", Metal Storm weapon systems currently are promoted in a variety of calibers and applications. One of such applications is the 40mm, multi-shot grenade launcher, that could be either mounted on the infantry rifle to create an enchanced-capability infantry weapon like the Australian AICW system, or to be mounted on stationary or vehicle platforms in multi-barrel configurations.

Key advantage of Metal Storm system is its mechanic simplicity. In fact, the standard Metal Storm grenade launching unit is no more than a single rifled barrel, loaded with several projectiles, stacked one upon the another. There are no loading mechanisms, no feed units nor magazines or belts - each barrel is a magazine itself. Projectiles are fired using powder charges, located in the hollow hase of each projectile, and there's no case left to extract and eject after each shot;Powder is ignited by the electric ignition system, wired to the electrinic fire control module through small ports in the wall of the barrel. When user press the firing button or trigger, electronic fire control module sends the ignition impulse to the charge of the foremost projectile in the stack; when trigger is pressed for the second time, module ignites the second charge and then next, until barrel is empty. Once all the rounds in the barrel are shoot out, it can be removed from the host and then either collected and later sent to factory for reloading, or simply discarded.Current 40mm grenade launching module, developed for the AICW rifle/GL system, contains three grenades stacked one in front of another in single barrel. Each barrel has an electronic interface which is connected to the fire control unit, built into the host platform. This is about the simplest systems, at least from the operator's point of view (from developer's point of view, there's plenty of complications and difficulties, most of which seems to be already overcome).However, there is one drawback when Metal Storm system is compared to existing mechanically or manually reloaded systems - latter systems still can be fired once batteries are dry; Metal Storm always require some sort of electric power to operate. This problem may seem critical, especially for military purposes, but, actually, it is not. For example, several Soviet/Russian anti-tank grenade launchers (like RPG-16 orRPG-29) are built using electric rocket ingnition; necessary electricity is provided by the magneto-impulse generators, powered by the pull of the trigger. Same idea also could be possibly applied to the Metal Storm system.

During the late 1920s Waffenfabrik Solothurn, a Swiss private business that emerged in the watch-making industry but later turned to the production of small-armsparts, was bought by the German concern Rheinmetall, to serve as a research and development facility away from the watchful eyes of the Allied Control Commission, established in 1918 as a result of Treaties of Versailles. In 1929 Waffenfabrik Solothurn brought out its first practical machine gun, known by the factory as the S2-100, and in export catalogs as the MG 29. Next year Solothurn announced an updated version, the S2-200, also known as theMG 30. It was, in essence, a typical light machine gun – recoil operated and magazine fed, although Solothurn also offered a complicated universal tripod for this gun. The Solothurn MG30 earned its place in history by being adopted by Austria in 1930 and Hungary in 1931 (in both cases chambered for 8x56R ammunition), and it also served as the starting point for several German machine guns, such as the MG 15 (aircraft) and MG 34. It is also must be noted that most of components of the MG30 were produced in Austria at the Steyr factory; Solothurn carried out the final assembly and test-firing.

The Solothurn S2-200 machine gun is a short-recoil operated, air cooled, magazine-fed weapon. It uses a locking ring, which is located at the end of the barrel extension, to lock the bolt. Inside the locking ring, there are six sets of locking lugs, arranged as an interrupted thread. These lugs are mated with lugs cut at the rear of the bolt. Rotation of the ring, which locks and unlocks the bolt, is controlled by rollers mounted on the outside of the ring. Upon recoil, these rollers follow cam tracks cut into the receiver. The gun is of relatively simple design, with most parts having a round cross-section. The tubular receiver is an extension of the barrel jacket. The butt hosts a tube which contains the return spring and its guide. During disassembly, the butt is unlocked and rotated to disengage it from the receiver, then removed. This permits the entire barrel / bolt group to be pulled or shaken off the receiver for replacement. Since the bolt is held attached to the barrel extension, it needs to be removed from the hot barrel and attached to the cold one before reassembly; this procedure requires a heat-insulated glove to handle the hot barrel.The trigger is of the rocking type and allows for single shots and automatic fire. The selection of fire mode is made by pressing either the top (single shots) or bottom (automatic) part of the trigger.Ammunition feed is from curved box magazines, inserted from the left side; ejection is to the right.The gun is normally fitted with a folding bipod, although Solothurn also produced a sophisticated universal tripod, with a remote trigger and a traverse and elevation mechanism, and recoil buffers.Modifications:S2-100 / MG 29: a direct predecessor to the S2-200, made in very limited numbers in 1929-30. Key difference from S2-200 is that buttstock cannot be removed so quickly.MG 30 (Austria): same as S2-200 except for ammunition used – it was chambered for 8x56R rimmed ammunition, which required magazines of more curved shape31M (Hungary): same as MG 30.

German arms designer Andreas Wilhelm Schwarzlose patented a basic design for a machine gun in 1902. He subsequently sold his patent rights to the Steyr arms factory in Austria, which produced the first guns of the Schwarzlose pattern in 1905. After two years of trials and development, the military forces of the Empire adopted the Schwarzlose machine gun in 1907; this gun was also later adopted in a range of calibers by the Netherlands and Sweden (who both manufactured Schwarzlose machine guns under licence until the 1930s), and by Greece, Serbia, Romania, Bulgaria and Turkey – all before the World War I. In 1912 it was modified with the introduction of stronger parts and slightly reshaped retarding levers (struts). The primary visible difference between original M1907 guns and modified M1907/12 guns is the lack of the gap between the hump on the receiver and the barrel jacket on the latter guns.After the WWI and the fall of the Austro-Hungarian Empire, a great many Schwarzlose guns were adopted by smaller countries that emerged from the remains of the Empire, such as Czechoslovakia (which put the gun into production) and Hungary. Many Schwarzlose guns also went to Italy as war reparations, and subsequently saw some use during WW2, mostly in Africa in the original 8x50R caliber. Another user of Schwarzlose machine guns was Russia, which captured several thousands of Austrian machine guns during the early parts of World War One.The Schwarzlose machine gun, although overshadowed by more famous weapons such as the Maxim or Browning, has its own merits. It is quite simple in construction, robust in service, and usually quite reliable. Its drawbacks come from its basic design, which centers on a retarded-blowback action. This action calls for a relatively short barrel so that the chamber pressure drops before the case begins to leave the chamber; otherwise it would rupture – although when the Czechoslovak army converted their old 8x50R Schwarzlose machine guns to the more powerful 7.92x57 Mauser ammunition, they had no problems associated with high pressure, even with new, significantly longer barrels. Nevertheless, most of the Schwarzlose guns retained short barrels throughout their service life. This obviously limited the muzzle velocity and thus the maximum range and possible bullet penetration at any given range, compared with contemporary guns with a locked breech. The short barrel also called for a dedicated flash hider, to suppress the significant muzzle flash which otherwise would blind the gunner at night. Finally, the lack of primary extraction required an integral oiler, which squirted a small amount of oil into the chamber just before chambering the next round. Nevertheless, the Schwarzlose was a good weapon and saw considerable use through both world wars, although during the Second World War it was mostly relegated to second-line troops, fortifications and other such uses.

The Schwarzlose machine gun is a retarded-blowback operated, water cooled, belt-fed weapon that fires from a closed bolt. The method of operation requires a heavy breechblock, connected to the receiver through a pair of knee-joint struts. When the bolt is in battery, the struts are folded forward, with their joint axis lying relatively low above the barrel axis. Upon firing, the pressure of the powder gases acts on the breechblock through the base of the cartridge case. The rearward movement of the breechblock unfolds the struts, but because of a carefully arranged redirection of forces through the struts and joints, most of the initial pressure is transferred to the receiver. Upon further recoil, joint axis rises above the barrel, and thus the recoil force is re-distributed with more and more of it being used for bolt acceleration. Upon recoil, the bolt compresses a massive and powerful return spring which forces it forward and into battery once the recoil stroke is completed. The charging handle is attached to the axis of the forward strut, and has to be rotated back to cycle the bolt.Due to the lack of primary extraction, the Schwarzlose has to use oiled cartridges. To avoid the problems associated with factory-oiled or waxed ammunition (which tends to collect fine dust and then cause jams) the gun has an internal oiling system which squirts a small amount of oil into the chamber just before the chambering of each round. This system includes an oil reservoir, located in the receiver’s top cover, and a small oil pump, which is operated by the reciprocating bolt. The belt feed system is very simple, and involves few parts. The major part is the star-wheel, located in the lower left corner of receiver. Upon bolt recoil, the star-wheel is rotated for one step by the interaction of the cam surfaces on the bolt and the wheel. Each cartridge has to make three steps in the feed before being presented to the bolt for chambering, therefore initial belt loading requires three deliberate pulls on the charging handle. The feed direction is from the right side only, ejection being to the left.The trigger system also is of rather simply design. It involves a separate striker, a striker spring and a sear, mounted on the bolt. The sear is cocked by a lever attached to the rear bolt delaying strut, and this cocking movement adds to the retarding force applied to the bolt. After cocking the striker is held to the rear by the sear. The thumb trigger is located at the rear of the receiver, and once pushed by the operator, it holds the connection bar so it trips the sear when the bolt is in battery. A manual safety is located next to the trigger and blocks it unless pushed forward by the operator’s left thumb. Dual spade grips are located horizontally at either side of the receiver, and can be folded up for storage or transportation. The most common mounting was a tripod of solid construction, with tubular legs of adjustable height and traverse and elevation mechanisms. An optional armored shield was available for this gun, which was unusual in that it also provided frontal and lateral armored protection for the thin metal of the water jacket. Alternatively, a low-height, lightweight tripod was provided for the “light” role. This tripod had no traverse and elevation mechanisms.

diagram of the Greener-improved Martiny action, as used in Greener police guns

special 14 gauge shot shell for Greener police gun Mark III

Caliber

12 Gauge or 14 Gauge Greener

Type

Single shot

Overall length

1060 mm

Barrel length

610 mm

Weight, empty

3,5 kg

Magazine capacity

-

The Greener police shotgun is one of most unusual fighting shotguns which were employed by law enforcement organizations throughout former British empire. Despite its obsolete design (which traces its roots as far back as 1860s) Greener police gun can be still encountered in hands of police officers in some more remote parts of the world, mostly in Asia and Africa.

Story of the Greener police gun began shortly after the WW1, when British colonial police forces requested a weapon, suitable for riot control and prison guard duty. Another request was that the gun should use proprietary ammunition, not available through commercial channels. This was requested to made illegal use of guns, stolen or taken away from police more complicated for criminals. This request was fullfilled by famous British gunmaker W.W. Greener, who developed a single-shot shotgun, based on the long-obsolete but rugged Martiny single-shot action. This new gun fired proprietary 14 gauge shells, loaded with shot, and featured very rugged wooden full stock with steel nose cap and buttplate, so it can be safely and routinely used not only as a gun, but also as a club, banging doors and occasional hot heads in the course of upkeeping the law and order.

Greener police gun mark I appeared in around 1921, and tens of thousands were delivered to organisations like Egyptean colonial police etc. However, it was soon discovered that criminals, who managed to get hold on Greener guns, used standard 16 gauge shells, tightly wrapped into paper or tape to fire from Greener guns. To made commercial ammunition completely unusable, Greener responded with improved design, Greener police gun mark III. This gun used proprietary ammunition with bottlenecked case made of brass, with thick rim. Base of the case was roughly same as standard 12 gauge case, but toward the forward end of the shell it has reduced diameter equivalent to 14 gauge shell size. To further complicate illegal use of its police shotgun, Greener provided its Mark III guns with trident-shaped strikers. Greener police shells had grooved base and recessed primers, and attempt to fire any commercially available shell from Greener gun would fail every time as the side projections of the striker would hit the flat base of the shell, stopping the central part (the firing pin itself) before it can reach the primer. Some Greener Mark III police guns were also made to fire standard, commercially available 12 gauge ammunition or Mark I 14 gauge straight case ammunition.

Typical 14 Gauge cartridges available for Greener police gun were usually loaded by Kynoch with 30-36 gram of lead shot of small or medium size.

The Greener police shot gun Mark III is a single shot weapon. It uses Martiny type hinged block action, controleld by a lever located below the stock. Pulling the lever down and forward will rotate (drop) the front of breechblock down, exposing the chamber and extracting the fired shell. Fresh round then can be chambered and breech block raised by pulling the lever up. Gun is striker fired, and internal striker is cocked automatically as the breech block is opened. Manual safety is provided on the right side of the receiver. Greener police shot gun is fitted into two-piece wooden stock of solid construction, with steel nose cap and steel buttplate. On some Greener guns, nose cap was provided with bayonet mount, to achieve more intimidating effect on rioters or prisoners.

John Moses Browning, the legendary American gun designer, invented thefirst practical self-loading shotgun in 1898. In fact, Browning designed and patented three different systems, but finally choose the last one to go ahead. It must be noted, that at the time the autoloading shotgun was something of absolute novelty, and the task of designing such gun was severely complicated by the fact that the switch over from black powder to smokeless ammunition was well under way, and general quality of shotgun ammunition was rather uneven,to say the least. Nevertheless, Browning managed to make hist prototype model work, and work well. He first offered this shotgun to Winchester,which was the sole buyer for his designs from 1886 on. However, severe technical conservatism on the part of the Winchester's boss,T.G.Bennett, and financial disagreements (Browning insisted on royalty-based payments, but Winchester at the time always bought new designs for fixed amount of money) resulted in break between the designer and the company. Browning then turned to Remington, but tragicdeath of the Remington's president from hear attack just minutes before scheduled meeting with Browning put an end to this route as well. Browning thenturned to the Belgian company Fabrique Nationale (FN), which at this time (1901) produced first Browning-designed self loading pistol (M1900)as fast as it could be made. FN management greeted Browning and his new gun with great enthusiasm, and in a short while FN produced the first FN Browning autoloading shotgun, known as Browning Auto 5, or A-5 inshort. Browning himself ordered 10,000 A-5 shotguns from the first batch for sales and distribution in USA, and sold all 10 thousands in about a year. Following the introduction of the new, increased custom tariffs by US government, Browning found that it was economically not reasonable to import more A-5 guns into USA, so he pursued FN to release rights tomake and sell Browning auto loading shotgun on US market to RemingtonArms Co (FN originally had worldwide rights for manufacture of Auto 5).In 1906 Remington offered the Browning-designed auto loading shotgun as Model 11, and manufactured it without interruption until 1947, with well over 800,000 guns made. Between 1949 and 1968 Remington also produced an updated (lightened and streamlined) version of the Browning's design, known as Remington Model 11-48. The FN produced Browning Auto 5 shotguns continuously (with interruptions for German occupation during both World Wars) until 1999, making Auto-5 probably the most successful and longest-producing sporting shotgun in the history. Overall output of Auto-5 shotguns made and sold by FN (During WW2, A-5 shotguns were made for Browning Arms Co by Remington, and since mid-1970s Auto-5 shotguns were also produced for FN in Japan by Miroku, under FN license) over the century well exceeds two million guns (2,000,000th Auto-5 was produced in 1970). Total estimate of worldwide production numbers for this legendary Browning design is well over three million guns. Copies and clones of the Auto-5 shotgun were also manufactured in Italy by Franchi and Breda, in USA by Savage and in USSR / Russia by TOZ, and by some other manufacturers around the world. Many Auto-5 guns, made many decades before, are still used for hunting and shooting today, but, as time goes, Browning Auto-5 shotguns increasingly become collector's pieces.

Over the time, both FN and Remington produced wide variety of versions of the basic design. Hunting guns were made with plain or ribbed barrels of various lengths and gauges(12, 16 and 20), with magazine capacities of 4 or 2 rounds, various stocks, finishes etc. For police and military applications, FN andRemington created shorter-barreled shotguns with plain barrels. Many Remington guns have seen extensive use by US police and securityservices; US military also used Remington shotguns to train AA and aircraft gunners in shooting at fast-moving flying targets (clay pigeons), usingtraditionally stocked guns or guns, mounted in special fixtures to emulate aircraft machine guns. Belgian-made guns have seen less military service, although British army issued more than few A-5 shotguns as L32A1 during Malay counter-insurgency operations and later.

BrowningAuto-5 shotgun uses recoiling barrel to operate its action. The system is of so-called long-recoil type, as barrel and bolt recoil together for entire length of the recoil stroke, being securely locked by pivoting piece, installed in the bolt. This piece, when pivoted up, engages the cut in the barrel extension with its large locking lug. Upon completion of the full recoil path, the bolt is arrested in the rearmost position,and the locking piece inside it is tipped down to release the barrel.Barrel, under pressure of its own return spring, located around the magazine tube, slams forward, leaving the empty shell on the bolt face.Once the empty shell is clear of the barrel, it is ejected out of the gun. When barrel comes to the rest in the forward position, it automatically releases bolt catch, allowing the bolt to run forward,picking the fresh cartridge from the raised cartridge lifter, and locking the to the barrel at the end of the forward run. Bolt return spring is located in the butt. To achieve reliable functioning with wide variety of loads, Browning used self-adjusting friction brake in the recoil system, which consisted of several (one or two, dependingon the exact model) friction rings, located around the magazine tube.The tubular magazine holds four rounds; fifth one can be loaded into the chamber, making the total capacity of five rounds. One importantdifference between FN Auto-5 and Remington Model 11 shotguns is that the FN guns had a magazine cut-off lever, located on the left side of the receiver. This lever, when turned to the rear, locks the cartridgesin the magazine, allowing for quick replacement of the loaded round with another (presumably, with different type of projectile(s), i.e.shot to slug or vice versa). Remington shotguns did not have this feature.